root

Theirs nothing special in doing this, it can be done by URL Rewriting methods OR you could simply structure the website so that the index page for the given year lives in a folder named after that year (simplest method)

Then your front page in the htdocs can be used as the current year, when you want to update the year, you copy the page to a new folder, put all its supporting material like images in there with it so that each year the content is preserved and if you use a database, you could simply export to a SQLite file in that folder and modify the page database so that each page is completely independent and any major changes will not affect the previous years.